Field of the Invention
Embodiments of the present invention relate generally to computer processing and, more specifically, to generating support material for three-dimensional printing.
Description of the Related Art
A typical three-dimensional (3D) printer generates a 3D solid object based on a 3D printable digital model, such as a 3D mesh of triangles. In operation, the 3D printer creates the 3D object from bottom to top. For instance, if the digital model were to represent a candy cane, then the 3D printer would print successive layers of material beginning with a layer corresponding to the bottom of the stem and ending with a layer corresponding to the top of the hook. To avoid subsequent un-supported layers (such as the hook of a candy-cane) collapsing and/or drooping onto proceeding layers or the ground due to gravity during the printing process, 3D printers typically generate bloated 3D objects.
Such bloated 3D objects include not only material that represents the 3D object but also “support structures” that ensure the integrity of the material that forms the 3D object throughout the 3D printing process. Often, the 3D printer generates support structures in a different type of material (support material) than the material used to generate the geometries associated with the 3D object. After the 3D printer generates the bloated 3D object, then a designer performs post-processing operations to remove the now-extraneous support material and reveal the desired 3D object. For instance, the designer may break off or dissolve the support material.
In one approach to generating support material, the 3D printer first identifies overhanging surfaces of the 3D model that require support. The 3D printer then projects these overhanging surfaces to the ground, creating projected regions. Finally, the 3D printer fills the volume between each overhanging surface and the corresponding projected region with support material. Again, after the 3D printer has generated the 3D model, the support material is superfluous.
One limitation to filling volumes with support material is that generating the support material is time consuming. Consequently, fabricating volumes of support material between overhanging surfaces and the ground may increase the execution time of the 3D printer to unacceptable levels. Further, the support material is often costly. In general, as the amount of support material that the 3D printer generates increases, the cost-effectiveness of 3D printing decreases.
As the foregoing illustrates, what is needed in the art are more effective techniques for generating support material for 3D printing.